Computer



L. W. IMM

COMPUTER May 18, 1954 2 Sheets-Sheet 1 Filed March 14, 1949 IN VEN TOR Zzms H4 [MM May 18, 1954. 1.. w. [MM 2,678,772

COMPUTER Filed March 14, 1949 2 Sheets-Sheet 2 Patented May 18, 1954 1. li ENT OFFICE COIVIPUTER Lewis W. 1mm, Pacoima, Calif., assignor'to Libra- .scope, Incorporated, Burbank, Calif.,-a-corporation of California Application Marchl l, 1949, Serial No. 8'1,'339

9 Claims. 1

The present invention relates to computing mechanisms and particularly to a novel computer for deriving from progressively changing input data capable of representation by one or more mathematical curves, anoutput oroutputs representative of simple or weighted iunctio'nsoi such curve or curves.

The simplest .form of problem which computers embodying the present invention are designed to solve is that of determining the magnitude of an area bounded in whole or in part by a curve; examples of which are graphicalrepresentations of data in which the representative curve defines an area bounded on two sides by'rectilinear X and Y axes, and map areas in which all .sidesirnay be bonded by curves.

Weighting of the data represented by the curve dealt with introduces complications into the problem varying in degree according to whether such weighting is effected according to (l a constant value, (2) progressively changing values capable of representation by a second curve, or (3) changing values which arefuncti'ons of-the progressively changing values represented bythe single curve being dealt with. Weighting by a constant value involves no substantial complication, but weighting in accordance with either a second curve or in accordance with a function of the primary curve involves problems of computer design which iti's a primary object of the present invention to solve.

Specific applications for computers embodying the present invention are many and various; including, in the category presenting computations in which data represented'by the primary input curve must be weighted in accordance with a second curve, (1) geophysical and marine exploration apparatus, in which a primary curve constructed from data representing a series of time intervals between transmission of sound impulses and receipt of echoes must 'be weighted in accordance with a curve representative of varying rates oi sound transmission in different media or the same media at different temperatures; and (2) tristirnulus computers, in which a primary curve constructed from data representing percentages of light reflection at progressively diiie'rin'g wavelengths must be weighted in accordance with a curve representative of varying retinal sensitivity to various wavelengths. Included.in'thecategory presenting computations in which data represented by the primary input curve must be weighted in accordance with a iunctionof the primary curve itself are 1) centroid computers, in which the determination ofthe location of the centroid'oi'an area boundedin whole or in part by a curve requires such'weighting'as hereinafter described; (2) computers for determining any other desired properties of the area bounded by the primary curve. This enumeration of specific applications is not, of course, exhaustive and is intended "to supply only examples of applications of computers embodying various novel features of the present invention.

Computations of the character described are performed, according to the present invention, by combinations including a'series of integrating devices having a common input and each provided with asecond input under the joint control of the common input and a weighting value input, which latter may be either a value derived from another curveor a value which is a tune tion of the primary input curve.

In the embodiment illustrated and described in this specification, however, the arrangement is one in which the weighting value input is a function of the primary input curve, since it will be clear to those skilled in the art that modification of this arrangement to provide for weighting by-a separate'eurveinv'olvesmerely the omission of parts.

Additional object's an'd advantages of the invention will be-apparent from the following description taken in conjunction with the drawings forming part of this specification, and in which:

Figure l is a schematic diagram of an em bodiment of the computing device of the invention; and

Figure 2 isa view showingthe essential structural details of the computing device of Figure 1.

Referring to the drawings vfor more specific details of the invention, and with immediate reference to the functional-schematic view of Figure 1, it indicates a closed curve located in a certainrelation toeoordinateaxesX and Y and enclosing an irregular area !2, various properties of which it is desired to ascertain. .For example it is desired .that the numerical units of area enclosed by the curve It! be ascertained, and that the centroid, the moment of inertia about the centroid, and the moment of inertia about the Yaxis of thearea bealso determined, preferably simultaneously. To achieve this purpose, it is necessary that some form of scanning means be provided so that certain instantaneous components of the area will be continuously .iurnish d during the scanning operation. As a scanning means for irregular curves, such as it, where neither of the coordinate axes forms a boundary of the enclosed area, I prefer to use a pair of balanced light sources, not shown, a scanning slit I l driven at a constant speed across the area along the X axis, as by a motor It, a photoelectrio bridge indicated generally at is and comprising a pair of photoelectric cells 2%] and 22 located in balancing relation in bridge circuit 2 2 to resistors 26 and 28, an amplifier 3t connected to circuit 24; by leads 32 and 34, a servo motor 36 driven by unbalance of the circuit 24 in a direction tending to correct this unbalance, and a shutter 38 driven by the motor 36 and operative to restrict the amount of light received by cell 22 to that received by cell 20, as will hereinafter more clearly appear. A source of electrical excitation is adapted to be connected across points 40 and. 42 of the circuit 2 3.

The area I2 may be represented by a cut-out in a sheet of paper, or the like, fixed in relation to the coordinate axes X and Y, although the area may be represented in any manner in which it can be photoelectrically distinguished. The light sources, not shown, and the cells 28 and 22 are so arranged that cell receives only that amount of light which will pass through the instantaneous mutually inclusive portions of slit i4 and area I2, while cell 22 is capable of receiving all the light passing through slit It.

It will be appreciated that when motor I5 is actuated to drive the slit in scanning movement along axis X, no light will be received by cell 29 until the slit coincides with area I2, but that meanwhile light has impinged on cell 22, causing unbalance or bridge circuit 24 and actuation of motor 36 through amplifier 30 to close shutter and balance the bridge circuit. As soon as the slit M in its scanning movement coincides with the area I2, light is received by cell 20, causing actuation of motor 36 and an opening of shutter 38 to allow cell 22 to receive the same amount of light. In this manner, motor 36 is continuously actuated in one direction or the other to cause the shutter to balance the incident light of cell 22 with that or cell 20, and since the light reccived by cell 26 is proportional to the instantaneous magnitude of the segment of area being scanned, the output of motor 36 is proportional to this instantaneous element of the area, which may be considered to be Y2-YL Referring particularly to Figure 2, this instantaneous area element, Y2Y1, is continuously fed through shaft 44, driven by motor 365, and gear 46, fixedly carried by said shaft, to a rack it in mesh with gear 46. The rack is connected to a rod extending into the housing 52 of an integrator '54 and secured to a ball carrier 55, the opposed contacting balls of which serve as a driving connection between the disk 58 and cylinder 68 of the integrator 55. Meanwhile, the instantaneous value of X is fed to the disk 58 through motor I6, shaft 62 driven thereby, gear 64 carried by shaft 62, gear 66 in mesh with gear 66, and shaft 68 mounting gear 66 at one end and disk 58 at the other end, and being journalled for rotation in housing 52. The disk 58 in rotating through the range of X2-X1 drives cylinder through the balls of the ball carrier 58, which, as has been seen, is being continuously reset to the instantaneous value of 'iz-Y1, with the re-- sult that the output of cylinder 66 through shaft 70 to counter 12 is equal to the following: f(Y2Y1)dX, between the limits of X2 and X1. The value of this summation is equal to the numerical value of the area I2 when the scanning operation is completed, with the result that the 4 value of the area may be directly read from counter I2.

As the area value is being summed up and transmitted to the counter "I2, other properties of the area I2 are being simultaneously ascertained. The determination of such other properties is accomplished by weighting the value of the area in accordance with the coordinate values of another curve, which may be either an empirical curve or a curve representing a function of the curve with respect to which the determination of area is being made. In the embodiment illustrated, the weighting curve is of the latter class and curves representing diiierent functions of the area being determined are employed for weighting purposes to determine the centroid and the moment of inertia about the Y axis.

The centroid of the area, which is a line parallel to the Y axis and passing through the center of gravity of the area, is determined with the following mechanism in the following manner. Shaft MI through gear 14 fixed to the shaft, rack It in mesh with the gear, and rod it connected to the rack feeds the value Y2Y1 into one side of a scissors multiplier linkage indicated gener ally at 8B, and which may be of the type described in Imm Patent No. 2,394,180. Shaft 62 through gear 82 fixed thereto, rack 84 in mesh with the gear, and rod 86 connected to the rack feeds the value X into the other side of the multiplier linkage 80, with the result that the multiplier output, X(Y2-Y1), is transmitted to arm 88 or first class lever 90 fulcrumed at etc, and from one end of lever 90 to rod 92 having the ball carrier 93 of integrator 94 secured thereto. At the same time gear 66 is feeding X, or the change in X, to gear 96 carried by shaft 98 connected to the integrator disk I00. lhe conjoint movement of carrier 93 and disk It!) imparts an output to cylinder I02 equal to the following:

between the limits of X2 and X1, the coordinate limits of X of the curve Iii. For purposes of brevity this summation may be written as fXdA where dA is the differential of the area i2. The value fXdA is fed by the output shaft 34 of cylinder I92 to gear I06 fixed thereto, and gear itlfi actuates rack IE8 and rod iii) connected thereto to feed this mentioned value into one side of a divider linkage indicated generally at H2 and corresponding in construction to the multiplier linkage previously described. The output of cylinder 60, which is the value of the area, or MA, is fed into the other side of divider linkage Il2 through gear H4, rack I16 and rod H3. The divider linkage H2, therefore, divides the one input value fXdA by the other input value MA, and the resulting quotient is equal to the weighted value of X, or the centroid of the area I2, which may be denoted as Xe. X0 is fed through the output side of the divider linkage H2 to rod I20 and rack I22 connected thereto, and rack I22 in mesh with gear I24 fixed on shaft E26 transmits the value of Xe to counter E23, where it may be directly read at the conclusion of the scanning operation, in terms of linear measure from the margin of the area at which scanning was commenced.

Concurrently with the above-described operation, yet another property of the area is being determined, and this is the moment of inertia of the area I2 about the Y axis, or MIY. This property is determined-as follows: The lower: end of'lever 9D isc-onnectedito-rod. I whichin turn is connected; toone. input. side of another. mule tiplier linkage; indicated generally. at v I32; Rod 86, which. feeds. the. instantaneous. value. of X into multiplier linkage. 80, also; feds. the,- same value into ,theother inputsideof multiplier linkage I32. Thus, thellinkage. I32. multiplies the value,X (.Y2-.Y1) byh-X, and theproduct is fed to crank lever I34 fulcrumed at I34a, which, being connected to rod I36, transmits this Value to the ball carrier I38 of an integrator indicated generally at I40, Gear 95 transmits the I value of the change inX between limits X1 and.

X2 ,to gear 114.2 in mesh therewith, andpintegrator disk Mil is rotated in proportion to this value by shaft, I connected to gear I42. The conjoint movement of disk Miandball carrier I38 results in an integration step, the. output of cylinder I48 being equal to fX (Y2Y1)d'X, or fX dA, between the values of X2 and X1. The moment of inertia, Mm, being equa1 to jX dA, is thus fed by shaft, I50. to counter. I52 where itmay be directly read at the conclusion of the scannin operation.

And yet another property, of the area I2 is simultaneously obtained by the. embodiment of the inventionfshown, and this property is the moment of inertia of the area 12 about the centroid X0. The equationto be solved is scribedin detail in the copending Imm.appli-..

cation Serial No. 508,231, filedOct-ober 29, 1943, new. Pat. 2,485,200.. Themotionof shaftlfliis imparted to one side .ofthedifierential through gear I66, and themotion of. shaft-I58 is imparted to the. other side of .thetdifierential through gear I68, with. the result thatrotation of outputshait I B l is equal to the difference in rotation between shafts-.126 and I 58,. which difference. equal to the squareof the centroid, or X?.. This .valueis transmittedthrough. bevel. gear IIIl carried. by

shaft IB Lto. bevel. gear I12:carried.by shaft "4,.

and from gear Ildcarriedby. shaft ill. to rack H8 in mesh Withgear I16. Rack. I18 through red I80 connected therewithfeeds. the value. Xe? into one side. of. another multiplier linkage indicated generally at I 82; Meanwhile, rod .I I8 feeds thevalue of thearea, orv A, into, the other side of multiplier linkage I82; andthev linkage output, X6 A, isitransmitted to. .firstclasslever J84 fulcrumed at. IBM, andifromlever. I8.4.,,to.rod I86,

rack I88, gear 199,..shaft: I.92,.and gearIIMWto one.

input side. of. another differential. mechanismindicated generally by 19.6: Motioniof .shaft. I50, which, it will be-remembered,..is proportional to Mrs, or-the moment-of inertiaofarea 12 about theY axis-is fed into.theiothersideoof. differem. tial I9B-by1gear I98; The output shaft 20.0 oithev differential I96. is; givenamotion equal: to the.

difference between the. input values, or

which diiference is-equaltoMxe, themoment of inertia of the area- I2; about the centroid Xc. The shaft: 250 actuates the counter 202 accordingly, with the result that the value of MIC may, be read directly from the;,counter at-the conclusion of the scanning operation.

It will beseenthat the computing device of the present inventionmakes it possiblefor, numerous properties. of curve-bounded areas to be simultaneously entertained, Other properties of an area, such as the radiusofigyration, which may be obtained bydividingthe moment of inertia by the area throughthe simple. provision of a divider linkage connectedacross the outputs of cylinders 6t and, I48: and having its output, side (with its movement amplified by servomo-tor,

if desired) feeding another counter orsimilar indicator, can be, solved, for; by slight modifications of the embodiment of the computing device shown.

It will be obvious, that the computing device may be as readily-usedto. ascertain the properties of areas defined by polarooordinates or other coordinate systems, and; that arbitrary properties may be accordedthearea defined by acurve, as by weighting the areain accordance withthe coordinate values of another curve, suohas a curve either representing a function of. the data represented by the main curve or: area, or, data having its origin in sources independent, of the. data represented by-the main curve,

.t is to, be further pointedoutthat various types of scannin means may beused to feed the: instantaneous, factorial values of, the area to the device. For example, if. the area-bounding. curve is regular and bounded: by acoordinate axis, a simple curve. tracer could, beused to. feed the values. of 01A to the computing mechanism, While if the curve is closed and; irregular, a specific linkage arrangement may .beprovided to achieve a mechanical scanning, or aspecially cut cam may be utilized for the samepurpose,

The invention is, therefore, to be; limited only by the scopeof the appended claims.

What I claim as .new and desire tor-secure by Letters Patent is:

1. In a computing devieeior thedetermination of properties of areas defined by curves, the combination of anintegrator having disk, cylinder and ball. elements, scanningmeans for an area defined bya curve having means producing an output motion. proportional to the instantaneous value of the segment, of area being scanned, means associated with said scanning means and having an output motionproportional to the rate of soanningmeans for receiving the rate of scanning. outputmotion from said scanning means and operabletotransmit said output motion to the disk element. of'theintegrator and to one input side. of 'a.multiplier unit, means for receiving the instantaneous. value output motion from said scanning meansandoperable to trans-- mit saidmotionto another input sideof said multiplier unit, means, interconnecting the output side of said multiplierum't and thebell elements of said integrator andgoperableto posi tion said ball elements in accordance with the output motion of said.unit, ,and means connects-5. to the-cylinder adaptedsto be actuated ,inproportion to the output motioniof saidcylinder.

2. In acomputingidevice. for the determination of properties of areas defined by curves, the combination of an integrator having disk, cylinder and ball elements, scanning means for an area defined by a curve having means producing an output motion proportional to the instantaneous value of the segment of area being scanned, means associated with said scanning means and having an output motion proportional to the rate of scanning, means for receiving the rate of scanning output motion from said actuating means and operable to transmit said output motion to the disk element of the integrator and to one input side of each of first and second multiplier units, means for receiving the instantaneous value output motion from said scanning 'lleans and operable to transmit said motion to another input side of said first multiplier unit, means interconnecting the output side of said first multiplier unit to another input side of said second multiplier unit and operable to transmit the motion of the former to the latter, means interconnecting the output side or" the second multiplier unit with the ball elements of said integrator and operable to position said ball elements in accordance with the output motion of said unit, and means connected to the cylinder adapted to be actuated in proportion to the ou put motion of said cylinder.

3. In a computing device for the determination of properties of areas defined by curves, the combination of first and second integrators, each having disk, cylinder and ball elements, scanning for an area defined by a curve having an output motion proportional to the instantaneous vaiue of the segment of area being scanned,

cans for actuating said scanning means and having an output motion proportional to the rate of scanning, means for receiving the output motion from said actuating means and operable to transmit said output motion to the disk elements oi each of said integrators and to an input of a multiplier unit, means for receiving the output motion from said scanning means and operable to transmit said output motion to the ball elements of said first integrator to position the cane and to another input of said multiplier means for receiving the output of said multiplier unit and operable to transmit said output to the ball elements of said second integrator to position the same, a divider unit having the two input sides thereof connected, respectively, to the cylinders of the first and second integrators and being adapted to receive the output motions of said cylinders, a first counter to receive the output motion of said first integrator cylinder, and a second counter to receive the output motion of said divider unit.

i. In a computing device for the determination of properties of areas defined by curves, the combination of first and second integrators, each having disk, cylinder and ball elements, scanning means for an area defined by a curve having means producing an output motion proportional to the instantaneous value of the segment of area being scanned, means for actuating said scanning means and having an output motion proportional to the rate of scanning, means for receiving the output motion from said actuating means and operable to transmit said output motion to the disk elements of each of said integrators and to the input sides of each of first and second multiplier units, means for receiving the output motion from said scanning means and operable to transmit said output motion to another input side of said first multiplier unit,

means connected to the output side of said first multiplier and operable to transmit the output motion thereof to the ball elements of said first integrator to position the same and to another input side of said second multiplier unit, means connected between the output side of said second multiplier unit and the ball elements of said second integrator to position the latter in accordance with the output motion of said unit, means connected to the cylinder of said first integrator for receiving the output motion thereof, and means connected to the cylinder of said second integrator for receiving the output motion thereof.

5. In a computing device for the determination of properties of areas defined by curves, the combination of first and second integrators, each having disk, cylinder and ball elements, scanning means for an area defined by a curve hav-- ing means producing an output motion proportional to the instantaneous value of the segment of area being scanned, means for actuating said scanning means and having an output motion proportional to the rate of scanning, means for receiving the output motion from said actuating means and operable to transmit said output motion to the disk elements of each of said integrators and to the input sides of each of first and second multiplier units, means for receiving the output motion from said scanning means and operable to transmit said output motion to the ball elements of said first integrator to position the same and to another input side oi said first multiplier unit, means for transmitting the motion of the output side of said first multiplier unit to another input side of said second multi plier unit, means interconnecting the output side of said second multiplier unit and the ball ele ments or said second integrator and adapted to position said ball elements in accordance with the motion of the output side of said second multiplier unit, means connected to the cylinder of said first integrator for receiving the output motion thereof, and means connected to the cylinder of said second integrator for receiving the output motion thereof.

6. In a computing device for the determination of properties of areas defined by curves, the combination of first, second and third integrators, each having disk, cylinder and ball elements, scanning means for an area defined by a curve having an output motion proportional to the instantaneous value of the segment of area being scanned, means for actuating said scanning means and having an output motion proportional to the rate of scanning, means for receiving the output motion from said actuating means and operable to transmit said output motion to the disk elements of each of said integrators and to inputs of first and second multiplier units, means for receiving the output motion from said scanning means and operable to transmit said output motion to the ball elements of said first integrator to position the same and to another input of said first multiplier unit, means for receiving the output of said first multiplier unit and operable to transmit said output to the ball elements of said second integrator to position the same and to another input of said second multiplier unit, means interconnecting the second multiplier unit with the ball elements of the third integrator and operable to position said ball elements in proportion to the output of said second multiplier unit, a first counter for receiving the output motion of the cylinder of said first integrator, a

divider unit for receiving the same output motion and also the output motion of the cylinder of said second integrator, a second counter for receiving the output motion of said divider unit, a value squaring mechanism to receive the output motion of said divider unit and adapted to transmit its output motion to an input side of a third multiplier unit, the other input side of said multiplier unit being adapted to receive the output motion of said first integrator cylinder, a differential mechanism for receiving the output motions of said third multiplier unit and said third integrator cylinder, and third and fourth counters for receiving, respectively, the output motions of said difierential mechanism and said third integrator cylinder.

7. In a computing device for the determination of properties of areas defined by curves, the combination of first, second and third integrators, each having disk, cylinder and ball elements, scanning means for an area defined by a curve having an output motion proportional to the instantaneous value of the segment of area being scanned, means for actuating said scanning means and having an output motion proportional to the rate of scanning, means for receiving the output motion from said actuating means and operable to transmit said output motion to the disk elements of each of said integrators and to inputs of first and second multiplier units, means for receiving the output motion from said scanning means and operable to transmit said output motion to the ball elements of said first integra tor to position the same and to another input of said first multiplier unit, means for receiving the output of said first multiplier unit and operable to transmit said output to the ball elements of said second integrator to position the same and to another input of said second multiplier unit, means interconnecting the second multiplier unit with the ball elements of the third integrator and operable to position said ball elements in proportion to the output of said second multiplier unit, a first counter for receiving the output motion of the cylinder of said first integrator, a 45 divider unit for receiving the same output motion and also the output motion of the cylinder 10 of said second integrator, a second counter for receiving the output motion of said divider unit, and a third counter for receiving the output motion of said third integrator cylinder.

8. In a computing device of the character described, an integrating device having a first input means and a second input means, and actuating mechanism for said second input means comprising a three-element scissor type multiplying linkage having a first element adjustable in a synchronized relationship with said first input means, a second element adjustable to represent a weighting value, and a third element jointly controlled by said first and second elements and having an operating connection with said second input means.

9. In a computing device of the character described, an integrating device having a disk, a cylinder, and adjustable ball means between said disk and said cylinder; means for driving the disk of said integrating device, and mechanism for adjusting the ball means of said integrating device comprising a three element scissor type multiplying linkage having a first element adjustable in a synchronized relationship with the driving means for the disk in said integrating device, a second element adjustable to represent a weighting value, and a third element jointly controlled by said first and second elements and having an operating connection with said ball means.

References Cited in the file of this patent UNITED STATES PATENTS 

